On 01/07, David Lechner wrote: > On 1/7/25 9:24 AM, Jonathan Santos wrote: > > Add adi,sync-in-spi property to enable synchronization over SPI. > > This should be used in the case when the GPIO cannot provide a > > pulse synchronous with the base MCLK signal. > > > > User can choose between SPI, GPIO synchronization or neither of them, > > but only if a external pulse can be provided, for example, by another > > device in a multidevice setup. > > > > While we are fixing up these bindings, we could add some more trivial things, > like power supplies. > > Also, the interrupt property could use a description since the chip has multiple > output pins. I assume it means the /DRDY pin? > Right! Yes, the interrupt pin refers to the /DRDY. > > Signed-off-by: Jonathan Santos <Jonathan.Santos@xxxxxxxxxx> > > --- > > .../bindings/iio/adc/adi,ad7768-1.yaml | 24 ++++++++++++++++++- > > 1 file changed, 23 insertions(+), 1 deletion(-) > > > > diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7768-1.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7768-1.yaml > > index 3ce59d4d065f..55cec27bfe60 100644 > > --- a/Documentation/devicetree/bindings/iio/adc/adi,ad7768-1.yaml > > +++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7768-1.yaml > > @@ -47,6 +47,15 @@ properties: > > in any way, for example if the filter decimation rate changes. > > As the line is active low, it should be marked GPIO_ACTIVE_LOW. > > > > + adi,sync-in-spi: > > If this is saying that SYNC_OUT is connected to SYNC_IN, then I think the name > should be something like adi,sync-in-sync-out. SPI seems irrelevant here since > we should just be describing how things are wired up, not how it is being used. > > But if we also need to consider the case where SYNC_OUT of one chip is connected > to SYNC_IN of another chip, we might want to consider using trigger-source > bindings instead (recently standardized in dtschema). > Do you mean the trigger-sources used for LEDs? I can try to see if it works, but would it handle the non-GPIO case? While testing a multidevice setup, I found it simpler to have a single device to manage everything. It lets us toggle the GPIO or /SYNC_OUT without referencing another device and makes simultaneous buffered reads easier. Maybe we could stick to synchronization within the chip for now. > > + description: > > + Enables synchronization of multiple devices over SPI. This property is > > + used when a signal synchronous to the base MCLK signal cannot be provided > > + via GPIO. It requires the SYNC_OUT pin to be connected to the SYNC_IN pin > > + on the ADC. In the case of multiple devices, the SYNC_OUT pin of one device > > + should be routed to the SYNC_IN pins of the other devices. > > + type: boolean > > + > > reset-gpios: > > maxItems: 1 > > > > @@ -65,7 +74,6 @@ required: > > - vref-supply > > - spi-cpol > > - spi-cpha > > - - adi,sync-in-gpios > > > > patternProperties: > > "^channel@([0-9]|1[0-5])$": > > @@ -89,6 +97,20 @@ patternProperties: > > allOf: > > - $ref: /schemas/spi/spi-peripheral-props.yaml# > > > > + # adi,sync-in-gpios and adi,sync-in-spi are mutually exclusive (neither is also valid) > > + - if: > > + required: > > + - adi,sync-in-gpios > > + then: > > + properties: > > + adi,sync-in-spi: false > > + - if: > > + required: > > + - adi,sync-in-spi > > + then: > > + properties: > > + adi,sync-in-gpios: false > > I think this can be simplified to using oneOf: to provide XOR validation > Right! > > + > > unevaluatedProperties: false > > > > examples: >
